1. Technical Field
This device relates to grinding machines that are used to grind cylindrical or rolling surfaces of a work roll on a rolling mill and other finishing rolls by incrementally advancing an abrasive belt over a platen movably engaged against the roll. This refinishing of work rolls is required as the rolls become worn and roughened during use. Conventionally the rolls are removed for grinding or are ground in their mounted position greatly reducing down time required for refinishing.
2. Description of Prior Art
Prior art devices of this type have relied on a variety of different structures to support and advance abrasive belts about a fixed point at variable speeds, see for example U.S. Pat. No. 2,810,480,U.S. Pat. No. 3,665,649, U.S. Pat. No. 4,292,767, U.S. Pat. No. 4,316,349 and U.S. Pat. No. 4,575,972.
In U.S. Pat. No. 2,810,480 a continuous abrasive belt is positioned against a flat work piece with variable tension. The belt travels in a single, continuous direction.
U.S. Pat. No. 3,665,649 discloses an endless grinding belt that can be positioned against a rod to grind and polish same.
U.S. Pat. No. 4,292,767 shows a belt grinder for a non-circular work piece rotating on its longitudinal axis. The relative pressure on the non-round work piece is required to be varied for maintaining even pressure and proper required finish. This device varies the pressure via a fluid motor advancing a cylinder according to a predetermined work piece shape requirement.
U.S. Pat. No. 4,316,349 discloses a portable abrasive belt finisher that uses a continuous abrasive belt supported by three rollers driven by a single drive motor.
U.S. Pat. No. 4,575,972 shows a portable grinding machine for use on rolling mills. The device uses a variable force against a pressure member engaging the abrasive belt traveling over. A load cell varies the force imparted against the pressure member by a pair of hydraulic piston and cylinder assemblies innerconnected to a spring loaded plunger that engages the pressure surface.